Telegraph system



may s, 192s. 1,536,753v

J. H. BELL TELEGRA PH SYSTEM Filed April '17, 1922 Patented May 5, 1925'.

, Pari-.Nr

JOHN Hmm ii-nnnfor soUfrH ORANGE; iiEWaERsEY, AssIGNonmo WESTERN ELEG- Tmc company, mearoanmnnor NEW Yomt, N; A CORPORATION .or NEW .YORK

instantanea Alain it, 19'22. sena no. tetit;`

fraai .une settles *it ahaha ima in which the false operation of the repeating means .is pievtta renewing are trasmission'o'f a .si naling y l Another d'jet is the provision of means to prevent the false4 operation ofthe tele'-y grapli sounderi'oljlowing the' transmissicn of a signaling impulse. I

nl teitgfaph' s :Staus utilizing repeating apparatus ii'hre'ilitelgraph impulses are t an'sni'ittldby lineans of 'the .o-pe'h" circuit rs 'stern overlines having'considerable electrosgatic capacity, there is a "tendency `for the .recording sounder to give y"false indications diie to vthe 'capacity dischargejofthje line aiecting the `hole station relay which should remain linoperative .following the op'e'rati'o'ii` of its `associated transmitting equipment. v n

" The4 invention lprovides an arrangementof apparatus at botli-thetrminal and repeater stations, tWliereby following n the transmission .of an 'impulse to line, thep'olarity of the charge of the distributedcapacityis such as torprevent the falseioperationiof the apparatus located at the i res'pectivey stations.

Therelis shio'wvn' ririfthe drawing, two line sections 4 and 5,' extending from terminal` stations X and Y respectively, to a repeater station A Where apparatus is located for repeating impulses from one line section to another Whichl vvill be free from bias and distortion. Connected With each ofthe line sections is a transmitting key whichserves to connect the line with a source of battery for causing the operation of the receiving apparatus at thelopposite end of the line through the nstrumentalities of the repeater equipment located at the repeater station tion.

lays having t-vvo coils,

- by having the A. strain' Caancaa wat a .cetera ai the transmitting key is what isr usually re` .ferred to as the vhoni'e station relay which controls, thrdugli its contactstlie actuation off sounder yforr givin" yto the operator an audible indieatioii oi the impulse transmitted from the distant stal l at the repeater station A comprises a pair of Vpblariied r# one serving as ati eratin'g coil, yvhile the othe'riunc'tions to noimallyjmaintairi theline ysection vvith which it is associated extended [to the operating @Giraf the lei-ay assbciated. in the taler uae- The equipment located character 'of ther section. The atter mentioned coil is noii-A mallyiiergized from a llocal source of bat'- tery through an adjustable, resistance there; by peirn'ittiri'g'of the variation of the ciiirent through its Winding or, in other yvords,iiiakf in'g it possible toiiicrease the-bias and-to adjustit-'over a Wide range.

The home sta-tion relay likethe relays at the repeater station,r is provided Aiv'itli afn operati-ng, and what may betermed a spr'acy` ing coil, the former of which serves to close the energizing circuit of fthe recording sounder,- Wh-ile the other maintains the circuit the sounder open during the nonoperation of the system.` Likewise, the lat'- .ter coil is maintained energlz'ed bycurrent furnished fioiiiwallocafl battery through an adjustable resistance in order that the bias may be adjusted through a ivide range, thus eliminating the use of biasing springs.

(living to the characteristics of signaling conducto'rs, especially those used for cable' Work, possessiiig considerable yelectrostatic capacity as represented by the condensers shown dotted, upon the impression dta-sig; maling impulse on the line conductor, the conductor becomes chargedand upon 'the restoration of the transmitting key to normal, this charge tends to leak oi through the Winding of the home station relay ther by causing its false operation. However, such objection is obviated by the use of po larized relays, as previously described, and

batteries at the respective ter,- minals of opposite polarity. With this arrangement, the discharge currents from the electrostatic capacity of the line in passing` through the home station relay will tend to make it space, that is.l to maintain the circuit of the recording sounder open, thus preventing its false operation.

The operation of the system just described is as follows:

Assume that it is desired to transmit message impulses from the station X to the st-ation Y. Upon the depression of the key 6, the source of battery 2O is connected with the terminal of the line section 4. Current thus transverses the line section 4 and passes through the coil 16 of the repeating relay associated with the line section 5. Current in passing through the coil 16 causes its energization thereby applying the positive polarity of battery 26 to the line section 5, this current in passing over this line section, traverses the normally closed contact of the key 24 and the winding of the coil 22. Upon the energization of the winding of the coil 22, the armature controlled thereby will be attracted for closing the circuit of the recording sounder thereby causing its operation to give an audible indication to the operator. During the time that the key 6 is depressed and the battery 20 is associated with line section 4, the distributed electrostatic capacity will be charged of a polarity in accordance with the polarity of the battery 2O and the electrostatic capacit-y of line section 5 will be charged of a polarity in accordance with the polarity of the battery 26. Upon the restoration of the key 6 and the repeating relay associated with the line section 4 to normal, the current generated by the discharge of the electrostatic capacity in line section 4 tends to pass through the coil 8 of the home station relay 7, and that in line section 5 through the coil 12 of the repeats ing relay associated with the line section 5. In the present system, however, the current passing through coil 8 will produce the same magnetic action as coil 9 and the current in coil 12 will produce the same magnetic action as coil 13. Thus, the discharge of the distributed electrostatic capacity will have no effect upon the home station and repeater station relays and the operator will receive no false indication due to such discharge.

Likewise, when the key 24 at the station Y is depressed for the transmission of message impulses, the coil 12 of the repeating relay associated with the line section 4 will be actuated for applying to the line section 4 an impulse in accordance with the depression of the key 24. The armature of this relay will, however, be restored to its normal condition due to the action of the coil 13 on the associated armature, which has normally applied thereto the battery from the source 14 through the adjustable resistance 15 upon the restoration of the key 24 to normal.

Although the invention has been shown in connection with one specific. form of tele` graph system, it is, of course, obvious that it may be applied to other types of systems without departing from the spirit and scope of the present invention. Y

The invention claimed is:

1.. A telegraph system provided for open circuit operation, a line conductor possessing considerable electrostatic capacity and divided into sections, repeating apparatus intermediate. the line sections comprising polarized relays, current sources of opposite polarity connected to the respective line sections by said relay, transmitting and receiving mechanisms associated with the terminal of each line section, means associated with said receiving mechanism for contro-lling its operation, and circuit connections effective following the impression of an impulse on a line section and the operation of a polarized relay for rendering said means effective to prevent the receiving mechanism from giving a false indication.

2. A telegraph system provided for open circuit operation, a line conductor possessing considerable electrostatic capacity and divided into sections, repeating apparatus intermediate said line sections comprising a pair of polarized relays, current sources of opposite polarity connected to the respective. line sections by said relays', transmitting and receiving mechanisms associated with the terminal of each line section, said receiving mechanism consistingof a home station relay and a recording sounder, and circuit connections effective Jfollowing the impression of an impulse on a line section and the operation of the repeating apparatus to cause the discharge of the electrostatic capacity of said line through a winding of said home station relay to insure the maintenance of its contacts open.

In witness whereof, I hereunto subscribe my name this 14th day of April A. D., 1922.

JOI-IN HUME BELL. 

